(1) component selected. In general, the thickness is difficult to form a small pump casting ferrite, which is easy to produce white. The silicon-carbon ratio increase can effectively prevent the generation of thin-walled office at the port will help improve casting organization uniformity, strength, hardness, and can reduce residual stresses. However, higher carbon equivalent, the opportunity to cast iron ferrite appearing significantly increased, which is to improve the overall performance of the casting is extremely unfavorable. According to the production test, we determined: Wc = 3.1% ~ 3.3%, wherein the carbon content is the core of the control, when the high carbon equivalent, may be appropriate to increase the manganese content in this range can be stable up to the requirements of UHT200.

(2) charge requirement. I am using the 3t / h two rows of large spacing cupola melting, using locally produced coke and pig iron, it may be 5% to 15% scrap. Scrap thickness ≥3mm, block greater than 1/5 the diameter of the furnace, it asked to do rust treatment. Block remaining charge of not more than 1/3 of the diameter of the furnace, in order to reduce the burning of silicon, try to use a lower silicon content alloy. To ensure the melting temperature should be chosen higher fixed carbon coke, and to ensure that fragmentation in the 90 ~ 130mm between.